Former Porirua sewerage plant workers: ‘We wouldn’t go swimming in there’
Former workers at Porirua’s wastewater plant say they wouldn’t go in the sea at the popular beach, having seen what goes in to the water there.
Both spoke anonymously but said while the plant used to be mostly be up to scratch, the region’s growing population meant it was over capacity, even before rain added to the system.
One happily took his children into the sea at Tītahi Bay in years past, but said he would no longer go in the sea and would not let his grandchildren in there.
“I’d reckon every time it rains they’d get a discharge,” he said.
The plant was built for a maximum population of 82,000 even without rain, he said.
Wellington Water chief wastewater adviser Steve Hutchinson maintained no raw sewage had entered the bay in the past 12 months.
The plant was designed to serve an 80,000 population, but had been upgraded to serve 121,000. The current population, covering Porirua and northern Wellington, is 96,000.
“Because the capacity has been upgraded, there have been no untreated wastewater bypass incidents over the past year,” he said. A weekend discharge on April 6 was wastewater that had gone through treatment but “was not fully treated”.
“The reason the water around the outfall pipe ... was murky was because it contained some of the micro-organisms that are used to treat waste water. These micro-organisms caused the discolouring in the water. The discharge did not contain raw sewage.”
Wellington Water took more than 18 hours last weekend to notify of that breach and, when it put up signs yesterday morning, they were not seen by mayor Anita Baker nor regular swimmer Michelle Warshawsky. Baker said the signs were “clearly are not adequate” and she had instructed her council to install four new signs up at the beach entrances.
Another former worker at the treatment plant said it used to put out “basically drinkable water”, but a growing population meant it could not keep up.
When this was driven by rain it was “diluted but not dissolved”, he said.
In May 2023, beach users, former plant workers and the Tītahi Bay Residents association submitted on the resource consent for the treatment plant saying it was unclear if the upgraded treatment plant was coping in wet conditions. “The continued and frequent discharge notifications ... are evidence of a plant, that despite recent hydraulic and UV upgrading, is not fit for purpose in wet weather, with increasing flows.”
The submission included a November 2022 apology from Wellington Water to “interested parties” after an “undisinfected waste water discharge” was not notified.